1211520233 has 16 divisors (see below), whose sum is σ = 1524593664. Its totient is φ = 935212560.

The previous prime is 1211520187. The next prime is 1211520241. The reversal of 1211520233 is 3320251121.

It is a cyclic number.

It is not a de Polignac number, because 1211520233 - 2²⁰ = 1210471657 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1211523233) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 65285 + ... + 81762.

It is an arithmetic number, because the mean of its divisors is an integer number (95287104).

Almost surely, 2^1211520233 is an apocalyptic number.

It is an amenable number.

1211520233 is a deficient number, since it is larger than the sum of its proper divisors (313073431).

1211520233 is a wasteful number, since it uses less digits than its factorization.

1211520233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147172.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 1211520233 is about 34806.8992155291. The cubic root of 1211520233 is about 1066.0483209877.

Adding to 1211520233 its reverse (3320251121), we get a palindrome (4531771354).

The spelling of 1211520233 in words is "one billion, two hundred eleven million, five hundred twenty thousand, two hundred thirty-three".